Comprehensive Biology Midterm Review: Cell Types, Macromolecules, Genetics, and Biotechnology

Prokaryotes

Simple cells with no nucleus or membrane-bound organelles. Example: Bacteria.

Eukaryotes

Complex cells with a nucleus and membrane-bound organelles (like mitochondria). Example: Plants, animals, fungi.

Lipids

Made from fatty acids and glycerol. Examples: Oils, Cholesterol, fatty acids.

Carbohydrates

Made up of carbon, hydrogen, and oxygen. Examples: sucrose, fructose, and glucose.

Proteins

Made from amino acids. Function: muscle builder and help with regulating hormones. Example: eggs, yogurt, lean meats.

Nucleic Acids

Made up of nitrogen-containing bases, phosphate groups, and sugar molecules. Includes DNA & RNA.

DNA

Double helix structure that stores genetic information. (Adenine & Thymine -> Guanine & Cytosine)

RNA

Acts as a messenger to read DNA's instructions and direct protein synthesis. Structure: single strand.

Monera

Single-celled, prokaryotic organisms (bacteria).

Protista

Mostly single-celled, eukaryotic organisms (algae, amoeba).

Fungi

Absorb nutrients, eukaryotic organisms (mushrooms, yeast).

Plantae

Multicellular organisms that make food by photosynthesis (plants).

Animalia

Multicellular organisms that eat food (animals, humans).

Central Dogma of Molecular Biology

Explains how genetic information flows: DNA → RNA → Protein.

Diploid

Cells with two sets of chromosomes. Example: body cells.

Haploid

Cells with one set of chromosomes. Example: sperm or eggs.

Homozygous

Having two identical alleles (HH or hh).

Heterozygous

Having two different alleles (Hh).

Recessive

Traits that are hidden unless two copies are present (aa).

Dominant

Traits that show when at least one copy is present (A).

Allele

A form of a gene (R or r for hair color).

Genotype

Genetic makeup (AA, Aa, or aa).

Phenotype

The physical trait seen (blue or brown eyes).

Prophase

Chromosomes become visible, nuclear membrane breaks down.

Metaphase

Chromosomes line up in the middle.

Anaphase

Chromosomes pull apart to opposite sides.

Telophase

Two new nuclei form.

Cytokinesis

Cell splits into two identical cells.

Pros of Biotechnology

Helps cure diseases (gene therapy), makes GMOs that grow faster and resist pests, produces insulin for diabetics.

Cons of Biotechnology

Raises ethical questions (gene editing, cloning), possible environmental risks (crossbreeding of GMOs), can cause unequal access to new technology.

Examples of Biotechnology

CRISPR gene editing, GMO crops like pest-resistant corn, insulin made using bacteria.